Placement of the Genus Angelina Within Rhytismatales and Observations of Angelina Rufescens
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Placement of the genus Angelina within Rhytismatales and observations of Angelina rufescens The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Karakehian, J. M., K. F. LoBuglio, and D. H. Pfister. 2014. “Placement of the Genus Angelina Within Rhytismatales and Observations of Angelina Rufescens.” Mycologia 106 (1) (January 1): 154–162. doi:10.3852/13-174. Published Version doi:10.3852/13-174 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:30167530 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Mycologia, 106(1), 2014, pp. 154–162. DOI: 10.3852/13-174 # 2014 by The Mycological Society of America, Lawrence, KS 66044-8897 Placement of the genus Angelina within Rhytismatales and observations of Angelina rufescens Jason M. Karakehian1 Discomyceteae exsiccatae as No. 16 (Korf 1954). He Katherine F. LoBuglio referred us to a classic paper on this species by Donald H. Pfister Durand (1902), which Korf also cited in his treatment Farlow Herbarium of Harvard University, 22 Divinity of discomycetes (Korf 1973). Subsequent morpholog- Avenue, Cambridge, Massachusetts 02138 ical and sequence analyses resolved the placement of this genus not in the Dermateaceae, where Durand (1902) and Korf (1973) had placed it, but instead Abstract: Angelina rufescens is placed within the core among the core clade of Rhytismatales (Lantz et al. clade of Rhytismatales (Leotiomycetes, Pezizomyco- 2011). tina, Ascomycota) based on analysis of LSU and mtSSU rDNA. The only species in the genus, it MATERIALS AND METHODS produces distinctive ascomata that reoccur annually on wood and on the remains of its own previous Collection.—Photographs were taken in situ and collections fructifications, forming dense conglomerations of taken for cultural and morphological studies and molecular interlocking longitudinally elongated apothecia with sequencing. The remaining portions were dried at low gray hymenia. Known collections and references of A. temperature in a home food dehydrator and accessioned rufescens indicate that it is endemic to eastern and into FH (Karakehian 12040101). central United States. Morphological and cultural Culture.—A few hours after gathering A. rufescens, dis- characters are described with notes on ascomata charged spores were collected onto Difco PDA media in two development. No mitospores were observed in field 100 mm Petri dishes. Small sections of the substratum collections or in culture. Lectotypes are designated supporting 2–3 apothecia were removed from the collection for Hysterium rufescens and its synonym Ascobolus and placed on moistened filter paper elevated on four glass conglomeratus. Angelina rufescens is illustrated here for slides. Plates were rotated 90 degrees every 20 min, and the first time in the taxonomic literature. three regions of ejected ascospores were collected. The Key words: Hypoderma, lectotypification, Leotio- dishes were placed in a dark incubator at 23 C. Polysporous mycetes, Lewis David von Schweinitz, Lophodermium, subcultures were made by excising 2 mm cubes of spore- bearing media and placing them at multiple points in mitochondrial SSU, Nils Peter Angelin, nuclear LSU, 100 mm dishes of Difco PDA, which were maintained at 23 C ontogeny, Rhytismataceae in darkness. Morphological observations.—Crush mounts from the living INTRODUCTION ascomata of A. rufescens were made in tap water or in 3% A collection of Angelina rufescens (Schwein.) Duby KOH and stained with phloxine in water and Congo red in was made in Carlisle, Massachusetts, United States 1 ammonia. Dried material was rehydrated in sealed Petri Apr 2012 from the underside of an oak log. The dishes on water-dampened filter paper, transferred to fungus had been observed at least 3 mo and had dilute gum arabic for 12 h and sectioned to 20 mmona freezing microtome. Dried material for crush mounts was fruited yearly on the same log since it first was rehydrated in 3% KOH or dipped in 70% ethanol, discovered five years earlier. Initially the identification rehydrated in water and stained with Congo red. Ascospore of this fungus even to the family level proved elusive. sizes are given from the average of 30 spores discharged It seemed to possess characters that were reminiscent from living apothecia onto a cover slip and mounted in of genera in both the Dermateaceae and Rhytismata- water. India ink was employed to detect the presence of ceae, which we could not reconcile. We decided to gelatinous spore sheaths. Observations of ascomatal devel- sequence it, and at the same time Richard P. Korf opment were made from living field-collected material identified the fungus as A. rufescens based on other (Karakehian 12090801). Microscopic observations were material from New England provided by our col- made with Nomarski and brightfield optics on Olympus league Lawrence Millman (Millman 2012). Korf BH-2 and Olympus BX40 compound microscopes and an noted that he had seen this fungus many years earlier Olympus SZX9 stereomicroscope. Drawings were made by JMK with a Leitz Laborlux compound microscope fitted around Ithaca, New York, and had issued it in his with a Leitz drawing tube. Submitted 27 May 2013; accepted for publication 20 Sep 2013. DNA Isolation, PCR and sequencing techniques.—DNA 1 Corresponding author. E-mail: [email protected] samples were obtained from living fruiting bodies of A. 154 KARAKEHIAN ET AL.: ANGELINA RUFESCENS (RHYTISMATALES) 155 rufescens (Karakehian 12040101). The DNA sample was Observations of ascomata development.—Hemispheri- used in PCR amplification and sequencing of the LSU and cal primordia, 100–150 mm diam, develop superficially mtSSU rDNA regions. DNA was extracted with the Qiagen on the substratum. These are at first hyaline but soon DNeasy Plant Mini Kit (cat. No. 69104). A 1/10 and 1/100 darken to pale yellow, orange then red with their apices dilution of the DNA was used for PCR amplification of the appearing granular, then tuberculate, from protruding mtSSU and LSU rDNA (ribosomal DNA) regions. The mtSSU was amplified with primers mrSSU1 and mrSSU3r cells (FIG. 2a, b). The primordia enlarge as hyaline (Zoller et al. 1999). Amplification of the LSU rDNA region hyphae emerge from their flanks and extend down, used primers LROR and LR5 (Monclavo et al. 2000). PCR infiltrating crevices in the surrounding substratum amplification, purification and sequencing was as described (FIG. 2c). These hyphae are septate, 3.5–5.5 mmdiam in Hansen et al. (2005). The GenBank accession numbers and sparsely encrusted with crystalline material. The for the LSU and mtSSU sequences for this isolate of A. primordia begin to elongate and enlarge laterally, rufescens are JX624162 and JX624163. An independent becoming hysterioid and darkening to dark brown- DNA extraction was performed from the living cultures black. Shallow apical sulci develop along their axes. The established in this study (see above). LSU and MtSSU DNA tissues surrounding the sulci and at the elongating ends sequences were determined to confirm the identity of the culture as A. rufescens. remain red-brown (FIG. 2d). Along the flanks of the primordia subtle longitudinal striations develop and Sequence analysis.—A NCBI (http://www.ncbi.nlm.nih. the hyphal extensions collapse forming a loose, flaky gov/) BLAST query of the LSU and mtSSU rDNA region pale brown tissue and leaving a white tomentose halo of determined that A. rufescens was most similar to genera in hyphal extensions only at the elongating ends (FIG. 2e). the Rhytismatales. LSU and mtSSU rDNA sequences from In transverse section the sulci are composed of 69 taxa representing members of the Rhytismatales sensu involute filamentous hyphae of the developing stricto (Lantz et al. 2011) were included in a combined apothecial margins. Crystaline material accumulates phylogenetic analyses of the LSU and mtSSU rDNA region. around the hyphae, ultimately forming a distinct split Phacidium lacerum, Lachnum bicolor and Pezicula carpinea (FIG. 2f). A thin pruinose layer of this material can be were used as outgroup taxa. These taxa and their GenBank accession numbers are in Lantz et al. (2011). observed developing around the sulci on the outer Alignment of DNA sequences was done with Clustal W surface of the primordia. through the Cipres Science Gateway (Miller et al. 2009) and Ascospores mature before the opening of the manually adjusted with Se-Al 2.0a8 (Rambaut 1996). The apothecium. In moist conditions, the prosenchyma- combined LSU and MtSSU DNA alignment is available from tous regions of the excipula swell, pushing the involute TreeBase under S14647. Regions of the DNA sequences that margins up and outward. Hymenial elements expand were highly divergent, as described by Lantz et al. (2011), and asci extend upward through the hamathecia, were not included in the analysis and resulted in a dataset of pushing the apothecium open further. Where asco- 1804 base pairs. DNA sequence alignments were analyzed as described by LoBuglio and Pfister (2010) with: MrBayes mata are densely gregarious, the flanks of the adjoining 3.0b4 (Ronquist and Heulsenbeck 2003) for obtaining apothecia swell tightly against each other, thus appear- Bayesian posterior probabilities (PP); maximum parsimony ing as interlocking gray hymenia. In senescent apothe- (MP) with PAUP 4.0b10 (Swofford 2002); and maximum cia where the excipula are heavily carbonized, the likelihood (ML) with RAxML-HPC2 on Abe through the apothecia tend to lose the ability to close. Cipres Science Gateway (Miller et al. 2009). Branch support for MP and ML analyses was determined by 1000 bootstrap replicates. TAXONOMY Angelina Fr., Summa veg. Scand., 2:358. 1849. RESULTS TYPE SPECIES: Ascobolus conglomeratus Schwein. Molecular phylogenetic analyses.—Results from phylo- genetic analyses of the combined LSU and mtSSU Angelina rufescens (Schwein.) Duby, Me´m. Soc. Phys. DNA sequences of 69 taxa, including A.